Tuning apparatus



C. T. NEAL ET AL TUNI NG APPARATUS Filed Jan. 28, 1925 INVEN TOR. y has 06.2,,

ATTORNEYS.

SIGNORS TO THE 0. ID. TUSKA EORATION OF CONNECTICUT.

TUNING APP 1-:;

Application filed January This invention relates to improvements in radio apparatus and more particularly to improvements in variable tuning elements for radio circuits.

In radio apparatus, especially radio receiving sets, it is common practice to adjust the variable rotatable tuning instruments of the circuit by a tuning dial carried by the shaft of the instrument, which dial is located outside the panel and carries graduations that may register with an index point such as an arrow or marker on the face of the panel so that the instrument may be adjusted to tune the'circuit.

In the case of receivers having a multiplicity of tuned stages or circuits, there are necessarily a number of dials each having certain graduations that must be in register with an equal number of arrows or points on the panel, so that in tuningsuch a receiver, the operator instinctively endeavors to simultaneously direct his attention to the several dials and markers and, as a consequence, fails to concentrate upon the registering of one dial and marker at a time, the result being that unnecessary labor is expended in the performance of what would be a simple task if the operator directed his whole attention to one location.

Also, the knob portions of the usual dials are so relatively small in diameter that they are not-easily grasped and it is difficult to move them through the small angular distances required for sharply tuning the circuits to obtain the required degree of selectivity. \Ve are aware that vernier devices such as separate operating shafts have been connected to that of the tuner by gears or the like to obtain a Vernier adjustment of the tuner but these devices are not altogether satisfactory since there is always present an appreciable amount of back lash or lost motion and entails what we believe to be superfluous mechanism.

According to one feature of our invention, we provide a circuit tuning apparatus that includes a dial of large diameter that has its lower peripheral edge adjacent the lower edge of the panel and which is pro vided with a roughened surface whereby it may be easily rotated by grasping its edge COMPANY, OF HARTFORD,

CHESTER '1. NEAID AND WALTER C. ROSS, 0F SPRINGFIELD,

MASMCHUSETTS, AS- CONNECTICUT, A COB- TITS.

25, 1925. Serial No. 5,400.

through relatively to obtain the defor sharply tuning the so that it may be moved small angular distances sired Vernier action circuit.

According to another novel feature, we

arrange the dials of adjacent circuits. in close relation so that the graduations thereof may be registered with a common point to enable the operator to concentrate his attention directly to one location during the tuning of said circuits. According to another novel feature of the invention, we provide dials having removable marking sections that are adapted to underlie a common marking guide, whereby each of the dials may be marked with deslgnating characters which may later be used to register the dial with the said guide. Other novel features and advantages will be apparent from the following description of the invention which is illustrated inthe embodiment at present preferred by means of the accompanying drawings, in which:

Fig. l is a front elevational view showing one form of the apparatus comprising a pair of dials for tuning independnt circuits of a receiver;

Fig. 2 is a section of Fig. 1; I

Fig. 3 is an enlarged fragmentary view showing the roughened edges of the dial.

The invention is capable of broad application wherever it is desired to operate a tuning element of a radio circuit, but will be herein described in pair of independently rotatable tuning elements that may be connected in independent tunable circuits.

In the drawings, dials 1 and 2 are provided that are adjustably fixed to rotatable shafts 3 of the tuning elements (not shown) by the usual set screws 3. The dials are preferably of a large diameter, nearly equal to the width of the panel P and element shafts are preferably located so that the adjacent sides of the dials are brought into close proximity while their lower sides are located adjacent and slightly above the lower edge of the panel P.

Each of the dials is provided with a central knob portion l, of the usual form,

taken on the line 2-2 connection with a the tuning adapted to be grasped by the hand for turning the dial through comparatively large angular distances while the peripheral edges thereof are bevelled, as shown in section in Fig. 2. The said bevelled edges are roughened or corrugated, as shown at 5 in the enlarged view Fig. 3, which facilitates the said bevelled edges being engaged by the thumb for turning the dial through smaller angular distances than is possible when the knob is grasped for a turning action.

A circular recessed groove 6 is provided in the front face of the dial that preferably has undercut or tapering sides, as shown in Fig. 2, and is adapted to receive a marking ring 7, which may be removably carried in said groove. The ring is preferably of such proportions with respect to the groove that it will be retained'therein by the tapering sides thereof, while a dowel 1-, located in one side of the groove, as best shown in Fig. 8, is adapted to interfit with a nick or out out in the edge of the ring 7 and is adapted to prevent a relative movement of the ring 7 with respect to the dial when in place in the groove thereof.

ring may be of paper or cardboard adapted to receive markings and is preferably adapted to be sprung into the groove, although other means may be employed for detachably fixing the marking area to the dial, the form shown. however, has been found to be entirely practicable.

Graduations and designations,

7 therefore, as shown, may be'provided on each dial that extend completely around the dial or only around 180 degrees thereof, and they may extend in corresponding or opposite directions, depending upon the use for which the apparatus is to be employed. For a practical application of the invention, however, we find that it is satisfactory to-have the graduations on dial. 1 run counterclockwise, while those on dial 2 run reversely or clockwise. lVith the graduations thus arranged and if each of the dials are engaged by the thumbs, as shown in dotted lines, a movement of the thumbs toward one another will increase the reading of the ia simultaneously, while as the thumbs are moved apart the readings will be simultaneously decreased.

A member 8 overlying the dials l and 2 is provided which is constructed to expose a portion of said dials and is arranged to function also as an indexing point with which the dials may be registered. The said member is preferably in the form of a plate which may be supported from the panel P by a central member 10 extending between the dials and integral with a flange or flanges 11 secured to the panel as shown. Windows or cut cuts 12 are provided in the face of the plate and are disposed so as to earner provide a central bar therebetween as shown. Notches 13 in the plate at the sides of the window and projections 9 at the sides of the plates are preferably disposed in an aligned relation so as to form a single reference line with which the scale or markings of the dials may be registered. The plate may take any form desired so as to overlie and expose portions of the dials and may be supported thereabove in any desired manner while various means such as marks or grooves may be disposed in an aligned relation on the plate to form the single reference guide line for the dials.

A rheostat operating knob B may be located intermediate the dials, as shown, wherein it will be readily accessible and the panel may be secured to the upper and lower sides C and C of a cabinet in the usual manner.

In operating and when tuning the circuits. the dials may be simultaneously moved by engaging the lower edges thereof with the thumbs, as shown, and when the timing has been accomplished, points may be marked on each of the rings 7 of the dials adjacent the notches 13 and designating characters or station letters written thereon through the Window, as is shown, or the graduations on the dials may be brought into register with the pointers 9 of the guide. 7

From the foregoing, it will be obvious that we have provided a tuning dial that may be easily and quickly manipulated since by its large diameter and roughened peripheral edges, it may be moved through relatively small angular distances.

Also, to those skilled in the art, it will be readily appreciated that the operator may concentrate his attention to one location, namely, the guide, since in the operation of this apparatus, both dials, whenever moved for registration, are registered with the same common guide member.

Having described the invention in the form at present preferred, we claim 1. Apparatus for operating variable rotatable tuning elements comprising in combmation, dials carried by said elements each having a scale and a zone for receiving markings. a member overlying said dials adapted to expose a corresponding portion of each of said dials and aligned reference guides carried bysaid member with which the said scales or markings of the lfllS may be registered to locate the dials in various positions of adjustment.

2. Apparatus for operating rotatable tunngelements of radio apparatus comprising in combination, dials carried by said elements each having a scale and a zone for receivingniarkings, a member overlving said dials having cut out portions at either side of a central bar for exposing correspondmg portions of each of said dials, and refthe dials may erence guides in aligned relation on said bar with which the markings or scales of be registered.

3. Apparatus for operating variable tuning elements of a radio set comprising in combination, a pair of adjacently located dials carrying markings, a member overlying said dials and having sight openings for exposing adjacent circumferential portions of each dial, and a dividing bar between said openings havin a common reference line adjacent to which the markings of each dial may be aligned.

4. Apparatus for operating variable tuning elements of a radio circuit comprising, dials carried by said elements each having a scale and a zone for receiving designating characters and a member having separate aligned reference guides with which the scales or characters of the, dials may be registered :30 as to locate the dials in definite positions of adjustment.

5. Apparatus for operating variable tuning elements of a radio circuit comprising,

' dials carried by said elements disposed to have their peripheral edges in close proximity and each having a scale and a zone for receiving designating characters and a guide member having guides on a single reference line common to both dials With which guides the scales or characters may be registered so as to locate the dials in definite positions of adjustment. 4

6. Apparatus for operating variable tuning elements of a radio circuit comprising, dials carried by said elements, a markin member and designating characters carrie by said dial, a guide member overlying adjacent portions of said dials having an opening for exposing a portion of the marking portion of each dial and having indexes for registering with the designating characters of said dials.

7 Apparatus for o e'rating variable tuning elements of a radio circuit comprising, dials carried by said elements having corrugated peripheral edges, marking rings removably carried by the dials within the periphery thereof, graduations carried by the dials within the markin rings, a guide member located above ad acent portions of the dials having an opening for exposing adjacent portions of said marking rings an points that are adapted to coincide with the graduations of said dials.

In testimony whereof we signatures.

have aflixed our CHESTER T. NEAL. -WALTER C. ROSS. 

